Display device and driving method

ABSTRACT

A display device and a driving method thereof are provided. The display device has a display panel and a field-sequential backlight module arranged opposite to the display panel. The display panel includes a light incident surface and a light exit surface arranged at a same side of the display panel. The field-sequential backlight module is disposed at a side of the display panel close to the light exit surface, and includes a plurality of light sources of at least three different colors. The display panel include a first substrate, a second substrate disposed opposite to the first substrate, and a liquid crystal layer sandwiched between the first substrate and the second substrate. The liquid crystal layer is configured to enable the display device to switch between an opaque or translucent state and a transparent state, without introducing any polarizers to the display device.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the priority of Chinese Patent Application No.201711026135.5, filed on Oct. 27, 2017, the entire contents of which areincorporated herein by reference.

FIELD OF THE DISCLOSURE

The present disclosure generally relates to the display technology and,more particularly, relates to a display device and a driving methodthereof.

BACKGROUND

With the development of display technology, user demands for displaydevices become more and more diversified. In certain applicationscenarios, a display device is desired to have substantially hightransparency, such as a glass window with a display function, a carwindow with a display function. Accordingly, transparent displaytechnology has become one of the research and development directions ofthe display technology.

However, the light transmittance of an existing transparent displaydevice is only about 30% and, more particular, the light transmittanceof a backlight module in the existing transparent display device issubstantially low, which may not meet the demands of the transparentdisplay technology.

The disclosed display device and driving method thereof are directed tosolve one or more problems set forth above and other problems.

BRIEF SUMMARY OF THE DISCLOSURE

One aspect of the present disclosure provides a display device. Thedisplay device comprises a display panel and a field-sequentialbacklight module arranged opposite to the display panel. The displaypanel includes a light incident surface and a light exit surfacearranged at a same side of the display panel. The field-sequentialbacklight module is disposed at a side of the display panel close to thelight exit surface, and includes a plurality of light sources of atleast three different colors. The display panel include a firstsubstrate, a second substrate disposed opposite to the first substrate,and a liquid crystal layer sandwiched between the first substrate andthe second substrate. The liquid crystal layer is configured to enablethe display device to switch between an opaque or translucent state anda transparent state, without introducing any polarizers to the displaydevice.

Another aspect of the present disclosure provides a driving method for adisplay panel comprising a display panel, wherein the display panelincludes a light incident surface and a light exit surface arranged at asame side of the display panel; and a field-sequential backlight modulearranged opposite to the display panel, wherein the field-sequentialbacklight module is disposed at a side of the display panel close to thelight exit surface, and the field-sequential backlight module includes aplurality of light sources of at least three different colors, whereinthe field-sequential backlight module includes a first-color lightsource, a second-color light source, and a third-color light source, thedisplay panel include a first substrate, a second substrate disposedopposite to the first substrate, and a liquid crystal layer sandwichedbetween the first substrate and the second substrate, and the liquidcrystal layer is configured to enable the display device to switchbetween an opaque or translucent state and a transparent state withoutintroducing any polarizers to the display device. The driving methodcomprises: displaying, by the display device, N frames of images in onesecond (1 s), where N is an integer multiple of 3; in each of the Nframes, emitting light, by only one of the first-color light source, thesecond-color light source, and the third-color light source; and in anythree consecutive frames of the N frames, emitting light, by thefirst-color light source, the second-color light source, and thethird-color light source, respectively, wherein images of the threeconsecutive frames are synthesized into one image observed by humaneyes.

Other aspects of the present disclosure can be understood by thoseskilled in the art in light of the description, the claims, and thedrawings of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings are merely examples for illustrative purposesaccording to various disclosed embodiments and are not intended to limitthe scope of the present disclosure.

FIG. 1 illustrate a cross-sectional view of an existing transparentdisplay device;

FIG. 2 illustrates a cross-sectional view of an exemplary display deviceconsistent with disclosed embodiments;

FIG. 3 illustrates a cross-sectional view of another exemplary displaydevice consistent with disclosed embodiments;

FIG. 4 illustrates a cross-sectional view of another exemplary displaydevice consistent with disclosed embodiments;

FIG. 5 illustrates a top view of an exemplary first substrate in anexemplary display device consistent with disclosed embodiments;

FIG. 6 illustrates a top view of another exemplary first substrate in anexemplary display device consistent with disclosed embodiments;

FIG. 7 illustrates a top view of another exemplary first substrate in anexemplary display device consistent with disclosed embodiments;

FIG. 8 illustrates a top view of another exemplary first substrate in anexemplary display device consistent with disclosed embodiments;

FIG. 9 illustrates a top view of another exemplary first substrate in anexemplary display device consistent with disclosed embodiments;

FIG. 10 illustrates a top view of another exemplary first substrate inan exemplary display device consistent with disclosed embodiments;

FIG. 11 illustrates a top view of another exemplary first substrate inan exemplary display device consistent with disclosed embodiments; and

FIG. 12 illustrates an exemplary driving scheme of an exemplary displaydevice driving method consistent with disclosed embodiments.

DETAILED DESCRIPTION

Reference will now be made in detail to exemplary embodiments of thedisclosure, which are illustrated in the accompanying drawings.Hereinafter, embodiments consistent with the disclosure will bedescribed with reference to drawings. In the drawings, the shape andsize may be exaggerated, distorted, or simplified for clarity. Whereverpossible, the same reference numbers will be used throughout thedrawings to refer to the same or like parts, and a detailed descriptionthereof may be omitted. It should be noted that the relative arrangementof the components and steps, the numerical expressions, and numericalvalues set forth in the exemplary embodiments do not limit the scope ofthe present disclosure unless it is specifically stated otherwise.

Further, in the present disclosure, the disclosed embodiments and thefeatures of the disclosed embodiments may be combined under conditionswithout conflicts. It is apparent that the described embodiments aresome but not all of the embodiments of the present disclosure. Based onthe disclosed embodiments, persons of ordinary skill in the art mayderive other embodiments consistent with the present disclosure, all ofwhich are within the scope of the present disclosure.

FIG. 1 illustrate a cross-sectional view of an existing transparentdisplay device. As shown in FIG. 1, the existing transparent displaydevice includes a display panel 010 and a backlight module 020. Thedisplay panel 010 itself does not emit light, and the backlight module020 provides a light source for the display panel 010. The display panel010 includes a first substrate 01, a second substrate 02 arrangedopposite to the first substrate 01, and a liquid crystal layer 03sandwiched between the first substrate 01 and the second substrate 02.The first substrate 01 includes a first polarizer 04, a plurality ofpixel electrodes 012, and a common electrode 011. The second substrate02 includes a plurality of color filters/color barriers 021 and a secondpolarizer 05.

The light emitted by the backlight module 020 sequentially passesthrough the first substrate 01, the liquid crystal layer 03, and thesecond substrate 02 to be received by human eyes. To improve thetransparency of the display panel 010, the color filters 021 are oftenmade of a highly transparent material.

However, in the existing transparent display device, the structures thatgreatly affect the transmittance of the display panel include the firstpolarizer 04, the second polarizer 05, and the color filters 021. Thelight emitted by the backlight module 020 has about 40% transmittanceafter passing through the first polarizer 04 and the second polarizer05, and about 30-80% transmittance after passing through the colorfilter 021. Thus, the light transmittance of the existing transparentdisplay device is only about 30% (40%*80%=32%) and, more particular, thelight transmittance of the backlight module 020 is substantially low,which may not meet the demands of the transparent display technology.

The present disclosure provides an improved display device and drivingmethod thereof, which are capable of improving the light transmittanceof the display device and thereby satisfying the demands of thetransparent display technology.

FIG. 2 illustrates a cross-sectional view of an exemplary display deviceconsistent with disclosed embodiments. As shown in FIG. 2, the displaydevice may include a display panel 100 and a field-sequential backlightmodule 200 arranged opposite to the display panel 100. The display panel100 may include a light incident surface 100A and a light exit surface100B arranged at the same side of the display panel 100. For example, asshown in FIG. 2, the display panel 100 may have a first side facing thefield-sequential backlight module 200 and an opposite second side, andboth the light incident surface 100A and the light exit surface 100B maybe arranged at the first side of the display panel 100. That is, thefirst side of the display panel 100 may be close to the light exitsurface 100B, while the second side of the display panel 100 may be faraway from the light exit surface 100B.

Further, the field-sequential backlight module 200 may be disposed onthe first side of the display panel 100, i.e., the side close to thelight exit surface 100B. The field-sequential backlight module 200 mayinclude a plurality of light sources of different colors which may bemixed together to generate white light. In one embodiment, thefield-sequential backlight module 200 may include a plurality of lightsources of at least three different colors.

The display panel 100 may include a first substrate 10, a secondsubstrate 20 disposed opposite to the first substrate 10, and a liquidcrystal layer 30 sandwiched between the first substrate 10 and thesecond substrate 20. The liquid crystal layer 30 may be configured toenable the display device to switch between an opaque or translucentstate for display images and a transparent state for fully transmittingthe light emitted from the field-sequential backlight module 200.

For example, the liquid crystal layer 30 may be configured to includepolymer-dispersed liquid crystals (PDLCs), or polymer network liquidcrystals (PNLCs). In one embodiment, as shown in FIG. 2, the liquidcrystal layer 30 may include polymer-dispersed liquid crystals (PDLCs).The first substrate 10 may include a plurality of pixels and a pluralityof pixel electrodes 11. The second substrate 20 may include a commonelectrode 21.

In the disclosed embodiments, the display panel 100 may include thelight incident surface 100A and the light exit surface 100B arranged atthe same side (i.e., the first side) of the display panel. Thefield-sequential backlight module 200 may be disposed on the first sideof the display panel 100, i.e., the side close to the light exit surface100B.

The light incident surface of the display panel refers to a surfacewhere the light of the backlight module enters the display panel. Thelight exit surface of the display panel refers to a surface where thelight of the backlight module is emitted after passing through thedisplay panel, and the light emitted at the light exit surface of thedisplay panel is finally received by human eyes. In the disclosedembodiments, both the light incident surface 100A and the light exitsurface 100B may be arranged at the same side of the display panel 100.That is, the light provided by the field-sequential backlight module 200may enter and exit the display panel 100 from the same side of thedisplay panel 100. Further, the light incident surface 100A, the lightexit surface 100B, the field-sequential backlight module 200, and thehuman eyes (i.e., observes) may be all located at the same side of thedisplay panel, i.e., the first side of the display panel.

In the disclosed embodiments, the liquid crystal layer 30 may includepolymer-dispersed liquid crystals (PDLCs), in which micron-scaled LCdroplets are dispersed in an organic solid polymer network. Without anelectric field, the optical axis of the small LC droplet has a freeorientation, and the refractive index of the LCs does not match therefractive index of the polymer. Thus, the light emitted by thefield-sequential backlight module 200 will be strongly scattered by theLC droplets when passing through the liquid crystal layer 30, resultingin an opaque state or a translucent state of the display device.

When an electric field is applied to the liquid crystal layer 30including PDLCs, the optical axis orientation of the LC droplets may beadjusted, such that the refractive index of the LCs may match therefractive index of the polymer, resulting a transparent state of thedisplay device. When the applied electric field is removed, the LCdroplets will restore the original scatting state to display images.

That is, the liquid crystal layer 30, which is configured with PDLCs,may enable the display device to switch between the opaque ortranslucent state for display images and the transparent state for fullytransmitting the light emitted from the field-sequential backlightmodule 200. Thus, polarizers may not be introduced to the discloseddisplay device for displaying images as compared to the existing displaydevices, instead, the disclosed display device may be able to displayimages with different transparency by simply adjusting the electricfield applied to the liquid crystal layer 30. That is, the discloseddisplay device may be able to display different grayscale images.

In addition, PDLCs have both refraction characteristics and reflectioncharacteristics. Through applying an electric field to the liquidcrystal layer 30, the refractivity and reflectivity of the LC dropletmay be adjusted. When the reflectivity of the LC droplet increases, therefractivity of the LC droplet may decrease. For example, light Lemitted by the field-sequential backlight module 200 enters the displaypanel 100 from the light incident surface 100A, due to the refractivityand reflectivity of the liquid crystal layer 30, part of the light L isreflected by the liquid crystal layer 30 to be reflected light L1, andpart of the light L is refracted by the liquid crystal layer 30 to berefracted light L2. The reflected light L1 exits the display panel 100from the light incident surface 100A again (as shown in FIG. 2, thelight incident surface 100A and the light exit surface 100B are bothdisposed on the first side of the display panel and, more particular,are the same surface of the display panel 100) and is finally receivedby the human eyes. The refracted light L2 exits the display panel 100from the other side of the display panel 100, i.e., the second side ofthe display panel 100.

In the disclosed embodiments, the display device may be able to achievesubstantially high reflectivity by adjusting the electric field appliedto the liquid crystal layer 30. Thus, when the light emitted by thefield-sequential backlight module 200 enters the display panel 100 fromthe light incident surface 100A, due to the refractivity andreflectivity of the liquid crystal layer 30, the light entering thedisplay panel 100 from the light incident surface 100A may be reflectedby the liquid crystal layer 30 to from the reflected light. Then thereflected light may exit the display panel 100 from the light incidentsurface 100A again, finally received by the human eyes.

That is, in the disclosed embodiments, during the operation of thedisplay device, i.e., when the display device is displaying images,human eyes receive the reflected light. In the transparent displaytechnology, because the display device is transparent, the ambient lightoutside the display device often affects the display performance of thedisplay device. However, in the disclosed embodiments, because humaneyes receive the reflected light from the display panel, the influenceof the ambient light on the display device may be suppressed, therebyimproving the display performance of the display device.

In the disclosed embodiments, the field-sequential backlight module 200may include light sources of at least three different colors, and lightof the at least three different colors may be mixed together to generatewhite light. In one embodiment, as shown in FIG. 2, the light sources ofthe at least three different colors may include three light sources ofthree different colors: a first-color light source 201, a second-colorlight source 202, a third-color light source 203. The first-color lightsource 201, the second-color light source 202, and the third-color lightsource 203 may emit light in a time-division manner, such that the lightsources of the three different colors may respectively enable thedisplay panel 100 to display images in the three different colors.

That is, the first-color light source 201 may enable the display panel100 to display a first-color image, the second-color light source 202may enable the display panel 100 to display a second-color image, andthe third-color light source 203 may enable the display panel 100 todisplay a third-color image, in the time-division manner. Thus, a fullcolor display device may be realized without introducing colorfilters/barriers to the display device. That is, the disclosed displaydevice may be free of color filters.

Further, the display panel 100 may include the first substrate 10 andthe second substrate 20 opposite to each other. The first substrate 10and the second substrate 20 each may be flexible or rigid. The firstsubstrate 10 and the second substrate 20 may be made of a material withhigh transparency, thereby further improving the light transmittance ofthe display device and satisfying the demands of the transparent displaytechnology.

In the disclosed embodiments, the pixel electrodes 11 may be disposed onthe first substrate 10, and the common electrode 21 may be disposed onthe second substrate 20. Through applying a voltage to the pixelelectrode 11 and the common electrode 21 respectively, an electric fieldmay be formed between the pixel electrode 11 and the common electrode21, which may control the reorientation of the LC molecules in thePDLCs, thereby displaying images of different transparency.

In the disclosed embodiments, the first substrate 10 may include theplurality of pixels and the plurality of pixel electrodes 11. In theexisting display device, each pixel often includes three sub-pixels,each sub-pixel includes a pixel electrode, and the three sub-pixelsdisplay three different colors. In the existing display device, variouselements, such as a signal line and a driving transistor, have to becorrespondingly provided for each sub-pixel and, thus, the lighttransmittance of the display panel is substantially low.

As a comparison, in the disclosed embodiments, sub-pixels may be nolonger arranged in the pixel, i.e., one pixel may be no longer dividedinto three sub-pixels. Thus, each pixel may only include one pixelelectrode, instead of three pixel electrodes in the existing displaydevice. Thus, given the same number of pixels, the disclosed displaydevice may have higher light transmittance than the existing displaydevice. That is, the disclosed display device may be able to improve thelight transmittance of the display device, as compared to the existingdisplay device.

In the disclosed embodiments, because polarizers and color filters areno longer introduced to the display device, given the lighttransmittance of the field-sequential backlight module 200 is about 90%and the light transmittance of the display panel 100 is about 90%, thelight transmittance of the display device may reach approximately 80%(90%*90%=81%), which may satisfy the demands of the transparent displaytechnology.

In the disclosed embodiments, on one hand, the display panel may includePDLCs, such that images of different gray scales may be displayed,without introducing any polarizers to the display panel. On the otherhand, the display device may include the field-sequential backlightmodule, such that images in multiple colors may be displayed withoutintroducing any color filters to the display panel. Because thedisclosed display panel does not include any polarizers and any colorfilters, i.e., the disclosed display panel is polarizer-free andcolor-filter-free, the light transmittance of the disclosed displaydevice may be significantly improved as compared to the existing displaydevice, thereby satisfying the demands of the transparent displaytechnology.

In one embodiment, as shown in FIG. 2, the field-sequential backlightmodule 200 may include a red light source 201, a green light source 202,and a blue light source 203. The display device may display N frames ofimages in one second (1 s), where N is an integer multiple of 3. Forexample, the display device may display 60 frames of images, 90 framesof images, 180 frames of images, etc., in one second. N may be anyappropriate numbers as long as N is an integer multiple of 3, which isnot limited by the present disclosure.

In each frame, only one of the red light source 201, the green lightsource 202, and the blue light source 203 may emit light. That is, whenthe red light source 201 emits light, the image displayed by the displaydevice is red; when the green light source 202 emits light, the imagedisplayed by the display device is green; and when the blue light source203 emits light, the image displayed by the display device is blue. Inany three consecutive frames of the N frames, the red light source 201,the green light source 202 and the blue light source 203 may emit lightrespectively.

It is understood that, on one hand, red, green, and blue are threeprimary colors of light, and the combination of red, green, and bluecolors can realize all of most colors. On the other hand, human eyeshave a function of persistence of vision, which refers to the opticalillusion that occurs when visual perception of an object does not ceasefor some time after the rays of light proceeding from it have ceased toenter the eyes. Based on the persistence of vision, a red image, a greenimage, and a blue image in three consecutive frames may be synthesizedinto one image including multiples colors. When the user watches thedisplay device, because the duration time of one frame is substantiallyshort (e.g., 0.0083 s when 120 frames are displayed in 1 s), the imageobserved by the user is usually a composite image of a red image, agreen image and a blue image, rather than a single-color image.

In the disclosed embodiments, through configuring the field-sequentialbacklight module 200 to include the red light source 201, the greenlight source 202 and the blue light source 203, the display device maybe able to display images of multiple colors based on the persistence ofvision of human eyes.

The number of the light sources, the arrangement of the light sources,and the color of the light sources are for illustrative purposes, andare not intended to limit the scope of the present disclosure. Inpractical applications, the number of the light sources and/or thearrangement of the light sources and/or the color of the light sourcesmay be determined according to various application scenarios.

Further, the light sources may be arranged in any appropriate positionsin the field-sequential backlight module 200. For example, in oneembodiment, as shown in FIG. 2, the light sources may be arranged at thelower side surface of the field-sequential backlight module 200, inanother embodiment, the light sources may be arranged at any appropriatesurfaces of the field-sequential backlight module 200.

FIG. 2 shows the number of the light sources is three, in anotherembodiment, the number of the light sources may be more than three. Forexample, six light sources may be arranged in the field-sequentialbacklight module 200, in which three light sources are arranged at thelower side surface of the field-sequential backlight module 200, and theremained three light sources are arranged the upper side surface of thefield-sequential backlight module 200.

FIG. 2 shows the field-sequential backlight module 200 may include red,green and blue color light sources, in another embodiment, thefield-sequential backlight module 200 may include light sources in anyappropriate colors, as long as the display device is able to displayimages of multiple colors based on the persistence of vision of humaneyes. For example, the field-sequential backlight module 200 may includered, green, blue and yellow color light sources.

Further, the light sources included in the field-sequential backlightmodule 200 may have any appropriate light-emitting structures. Forexample, the light sources included in the field-sequential backlightmodule 200 may be LEDs, OLEDs, LEDs/OLEDs plus fluorescentmaterial/quantum dots, which are not limited by the present disclosure.

FIG. 3 illustrates a cross-sectional view of another exemplary displaydevice consistent with disclosed embodiments. The similarities betweenFIG. 2 and FIG. 3 are not repeated here, while certain differences maybe explained.

As shown in FIG. 3, the pixel electrode 11 may include a reflective area12, and the reflective area 12 may include a reflective layer 121. Thesecond substrate 20 may be disposed on the first side of the displaypanel 100, i.e., the side facing the field-sequential backlight module200. The light emitted by the field-sequential backlight module 200 mayenter the liquid crystal layer 30 after passing through the secondsubstrate 20. The reflective area 12 may increase the light reflectionof the display panel 100 and, more particular, the reflective layer 121included in the reflective area 12 may have substantially highreflectivity, which may further improve the reflectivity of the displaydevice and the efficiency of the light emitted from the field-sequentialbacklight module 200.

For example, the reflective layer 121 may be made of metals which havesuperior light reflectivity. In one embodiment, the reflective layer 121may be made of silver.

In the disclosed embodiments, the reflective layer 121 may be directlydeposited/coated in the reflective region 12 of the pixel electrode 11.The reflective layer 121 and the pixel electrode 11 may be electricallyconnected, and the reflective layer 121 and the pixel electrode 11 mayhave the same electrical potential.

It should be noted that, because the liquid crystal layer 30 itself hassubstantially good light reflection, the area of the reflective layer121 may not have to be substantially large. In one embodiment, the arearatio of the reflective layer 121 to the pixel electrode 11 may beconfigured to be approximately 1:4.

FIG. 4 illustrates a cross-sectional view of another exemplary displaydevice consistent with disclosed embodiments. FIG. 5 illustrates a topview of an exemplary first substrate in an exemplary display deviceconsistent with disclosed embodiments. The similarities between FIG. 2and FIG. 4 are not repeated here, while certain differences may beexplained.

As shown in FIG. 4 and FIG. 5, the pixel electrode 11 may include areflective layer 13. The pixel electrode 11 may have a first side facingthe second substrate 20 and an opposite second side, and the reflectivelayer 13 may be disposed on the first side of the pixel electrode 11,i.e., the side facing the second substrate 20. The reflective layer 131may include a plurality of reflective elements 131, and an orthogonalprojection of the reflective element 131 onto the pixel electrode 11 maybe located inside the pixel electrode 11. The adjacent reflectiveelements 131 may be separated from each other, i.e., the reflectivelayer 131 is not a continuous reflective layer.

The reflective layer 13 may have substantially high reflectivity, whichmay further improve the reflectivity of the display device, and theefficiency of the light emitted from the field-sequential backlightmodule 200. For example, the reflective layer 13 may be made of metalswhich have superior light reflectivity. In one embodiment, thereflective layer 13 may be made of silver.

In one embodiment, the plurality of reflective element 131 may beone-to-one corresponding to the plurality of pixel electrode 11. In oneembodiment, an insulating layer may be disposed between the reflectivelayer 13 and the pixel electrode 11. In one embodiment, each reflectiveelement 131 in the reflective layer 13 may not receive the electricsignal, and in another embodiment, each reflective element 131 mayreceive the same electric signal as the corresponding pixel electrode11.

It should be noted that, because the liquid crystal layer 30 itself hassubstantially good light reflection, the area of the reflective element131 may not have to be substantially large. In one embodiment, the arearatio of the reflective element 131 to the pixel electrode 11 may beconfigured to be approximately 1:4.

The first substrate in the display device may have various structures,and certain exemplary structures will be explained in FIGS. 5-11.

FIG. 5 illustrates a top view of an exemplary first substrate in anexemplary display device consistent with disclosed embodiments. As shownin FIG. 5, the first substrate 100 may include a plurality of scanninglines 40 extending along a first direction X and arranged along a seconddirection Y, and a plurality of data lines 50 extending along the seconddirection Y and arranged along the first direction X. The seconddirection Y may intersect the first direction X. In one embodiment, asshown in FIG. 5, the first direction X may be perpendicular to thesecond direction Y.

The first substrate 100 may further include a plurality of thin-filmtransistors (TFTs) 60, which may be disposed one-to-one corresponding tothe plurality of the pixel electrodes 11. The pixel electrode 11 may beelectrically connected to the corresponding TFT 60.

In one embodiment, as shown in FIG. 5, each pixel electrode 11 may beprovided with a reflective element 131, and the orthogonal projection ofthe reflective element 131 onto the pixel electrode 11 may be locatedinside the pixel electrode 11.

In one embodiment, as shown in FIG. 5, the first substrate 100 may be anarray substrate which includes the plurality of TFTs 60 arranged in anarray. The TFT may include a gate, a source and a drain, in which thegate may be electrically connected to the scanning line 40, the sourcemay be electrically connected to the data line 50, and the drain may beelectrically connected to the pixel electrode 11.

In one embodiment, as shown in FIG. 5, the plurality of pixel electrodes11 may be arranged along the first direction X and the second directionY, forming a pixel electrode array and simplifying the manufacturingprocess.

FIG. 6 illustrates a top view of another exemplary first substrate in anexemplary display device consistent with disclosed embodiments. Thesimilarities between FIG. 6 and FIG. 5 are not repeated here, whilecertain differences may be explained.

As shown in FIG. 6, the plurality of pixel electrodes 11 may include aplurality of first pixel electrode columns 11A and a plurality of secondpixel electrode columns 11B alternately arranged in the first directionX. The first pixel electrode columns 11A and second pixel electrodecolumns 11B may extend in the second direction Y. That is, along thesecond direction Y, the pixel electrodes 11 arranged in the same columnmay form a pixel electrode column. Accordingly, the the plurality ofpixel electrodes 11 may include a plurality of pixel electrode columns,which may include the first pixel electrode columns 11A and the secondpixel electrode columns 11B.

The pixel electrode 11 in the first pixel electrode column 11A may beconfined in an area defined by two adjacent scanning lines 40 and twoadjacent data lines 50. The pixel electrode 11 in the second pixelelectrode column 11B may be confined in an area defined by two adjacentdata lines 50 and, meanwhile, the pixel electrode 11 in the second pixelelectrode column 11B may overlap with the scanning line 40.

Because color filters are not introduced to the disclosed displaydevice, the alignment between the pixel electrodes 11 and the colorfilters may be no longer taken into account, as compared to the existingdisplay devices. Thus, the arrangement of the pixel electrodes 11 maybecome more flexible and diversified. In addition, in the firstdirection X, the pixel electrodes 11 may be staggered, such that thecolor mixing may be enhanced when displaying images, the various displaydemands of different display devices may be satisfied, and the displayperformance of the display device may be enhanced.

In the display devices shown in FIGS. 5 and 6, the pixel electrode 11may have a rectangular shape, which is for illustrative purposes and isnot intended to limit the scope of the present disclosure. In practicalapplications, the shape of the pixel electrode 11 and thearrangement/layout of the pixel electrodes 11 may be determinedaccording to various application scenarios. The pixel electrodes 11 mayhave any appropriate shapes and any appropriate arrangement/layout.

FIG. 7 illustrates a top view of another exemplary first substrate in anexemplary display device consistent with disclosed embodiments. Thesimilarities between FIG. 7 and FIG. 5 are not repeated here, whilecertain differences may be explained.

As shown in FIG. 7, the pixel electrode 11 may have an irregularoctagonal shape. The pixel electrode 11 and the adjacent scanning line40 may be separated by a gap 402, and the pixel electrode 11 and theadjacent data line 50 may be separated by a gap 502. Electrodes may notbe provided in the gaps 502, 402 and, thus, an electric field forreorienting the LC molecules may not be formed in the gaps 502, 402.That is, the gaps 502, 402 may be transparent gaps 502, 402, whichremain in a transparent state all the time. Through forming thetransparent gap 502 between the pixel electrode 11 and the adjacent dataline 50, as well as the transparent gap 402 between the pixel electrode11 and the adjacent scanning line 40, the light transmittance of thedisplay panel may be further improved.

In another embodiment, the pixel electrode may have a shape differentfrom the irregular octagonal shape shown in FIG. 7, such as a pentagonalshape, or a hexagon shape, which is not limited by the presentdisclosure.

FIG. 8 illustrates a top view of another exemplary first substrate in anexemplary display device consistent with disclosed embodiments. Thesimilarities between FIG. 8 and FIG. 5 are not repeated here, whilecertain differences may be explained.

As shown in FIG. 8, the display device may include a plurality of longtransparent regions 70 without being disclosed with any pixel electrodes11 and any thin film transistors 60. The long transparent regions 70 mayfurther improve the light transmittance of the display device. Becausethe pixel electrode 11 is not provided in the long transparent region70, the liquid crystal layer in the long transparent region 70 may be nolonger affected by the electric field generated between the pixelelectrode 11 and the common electrode. That is, the long transparentregion 70 may remain in a transparent state all the time, therebyfurther improving the light transmittance of the display device.

Further, the plurality of scanning lines 40 may intersect the pluralityof data lines 50 to define a plurality of pixel regions 45. The pixelelectrode 11 may be disposed in the pixel region 45. The pixel region 45without being disclosed with any pixel electrodes 11 and any thin filmtransistors 60 may be the long transparent region 70.

The size of the long transparent region 70 may be determined todifferent application scenarios. In one embodiment, as shown in FIG. 6,the long transparent region 70 without being disclosed with any pixelelectrodes 11 and any thin film transistors 60 may be arranged in thepixel region 45 defined by the intersected scanning line 40 and dataline 50. That is, the size of one long transparent region 70 may beequal to the size of one pixel region 45. When the size of the longtransparent region 70 is substantially large, the display performance ofthe display device may be affected because the effective display areamay be reduced. When the size of the long transparent region 70 issubstantially small, the improvement of the light transmittance may benot obvious.

By configuring the size of the long transparent region 70 to beapproximately equal to the size of the pixel region 45, the influence onthe display performance of the display device may be substantiallysmall, while the light transmittance of the display device may beeffectively improved.

In addition, the long transparent region 70 may be formed withoutfabricating the pixel electrode 11 and the corresponding thin filmtransistor 60 in the long transparent region 70 and, thus, themanufacturing process may be simple without reducing the productionefficiency of the display devices.

FIGS. 9-11 illustrate top views of exemplary first substrates in anexemplary display device consistent with disclosed embodiments. Thesimilarities between FIG. 8 and FIGS. 9-11 are not repeated here, whilecertain differences may be explained.

As shown in FIG. 9, a plurality of pixel regions 45 may include aplurality of pixel groups 450. The pixel group 450 may include M numberof pixel regions 45 and one long transparent region 70, where M is apositive integer and

FIG. 9 shows the first substrate may include four pixel groups 450,which is for illustrative purposes and is not intended to limit thescope of the present disclosure. In practical applications, the firstsubstrate 100 in the display device may include any appropriate numberof pixel groups 450. For example, the first substrate 100 in the displaydevice may include five pixel groups 450, six pixel groups 450, seven ormore than seven pixel groups 450.

FIG. 9 shows each pixel group 450 may include four pixel regions 45 andone long transparent region 70, which is for illustrative purposes andis not intended to limit the scope of the present disclosure. Inpractical applications, the pixel group 450 may include four or morethan four pixel regions 45. For example, as shown in FIG. 10, the pixelgroup 450 may include nine pixel regions 45.

In the disclosed embodiments, only one long transparent region 70 may bedisposed in each pixel group 450, such that the distribution of theplurality of long transparent regions 70 may be substantially uniformand, accordingly, the display effect of the display device may besubstantially uniform. In another embodiment, more than one longtransparent regions 70 may be disposed in each pixel group 450, which isnot limited by the present disclosure.

The plurality of pixel groups 450 may have various arrangement/layout.For example, in the display device shown in FIGS. 9 and 10, the pixelgroups 450 may be arranged in an array, and the plurality of pixelgroups 450 may be directly adjacent to each other. That is, the pixelregions 45 may not be disposed between two adjacent pixel groups 450. Inanother embodiment, referring to FIG. 11, the pixel groups 450 and thepixel regions 45 may be alternately arranged. In particular, at leastone pixel region 45 may be disposed between two adjacent pixel groups450. The arrangement/layout of the plurality of pixel groups 450 may bedetermined according to various application, and is not limited by thepresent disclosure.

The present disclosure also provides a driving method for a displaydevice.

Referring to FIG. 2, the display device may include the display panel100 and the field-sequential backlight module 200 arranged opposite tothe display panel 100. The display panel 100 may include the lightincident surface 100A and the light exit surface 100B arranged at thesame side of the display panel. The field-sequential backlight module200 may be disposed on the side of the display panel close to the lightexit surface 100B.

The field-sequential backlight module 200 may include the plurality oflight sources of at least three different colors. In one embodiment, thefield-sequential backlight module 200 may include the first-color lightsource 201, the second-color light source 202, the third-color lightsource 203.

The display panel 100 may include the first substrate 10, the secondsubstrate 20 disposed opposite to the first substrate 10, and the liquidcrystal layer 30 sandwiched between the first substrate 10 and thesecond substrate 20. The liquid crystal layer 30 may includepolymer-dispersed liquid crystals (PDLCs). The first substrate 10 mayinclude the plurality of pixels and the plurality of pixel electrodes11. The second substrate 20 may include the common electrode 21.

FIG. 12 illustrates an exemplary driving scheme of an exemplary displaydevice driving method consistent with disclosed embodiments.

Referring to FIG. 2 and FIG. 12, the driving method for the displaypanel may include:

displaying, by the display device, N frames of images in one second (1s), where N is an integer multiple of 3;

in each frame, emitting light, by only one of the first-color lightsource 201, the second-color light source 202, and the third-color lightsource 203;

in any three consecutive frames of the N frames displayed in one second,emitting light, by the first-color light source 201, the second-colorlight source 202 and the third-color light source 203, respectively,wherein images of the three consecutive frames are synthesized into oneimage observed by the human eyes.

In particular, during the operation of the display device, N frames ofimages may be displayed in one second (1 s), and the duration time ofeach frame is 1/N second.

FIG. 12 illustrates an exemplary driving scheme of the first-color lightsource 201, the second-color light source 202, the third-color lightsource 203 in the field-sequential backlight module 200. As shown inFIG. 10, T1 denotes the duration time of the first frame, T2 denotes theduration time of the second frame, . . . TN−1 denotes the duration timeof the (N−1)-th frame, and TN denotes the duration time of the N-thframe. Among the waveforms of the first-color light source 201, thesecond-color light source 202, and the third-color light source 203, apeak indicates that a light source of a corresponding color receives anelectrical signal thereby emitting light.

In one embodiment, in the duration time T1 in the first frame, the lightsource of the first-color light source 201 may emit light; in theduration time T2 of the second frame, the second-color light source 202may emit light; in the duration time T3 of the third frame, thethird-color light source 203 may emit light; . . . , in the during timeof the (N−2)-th frame, the first-color light source 201 may emit light,in the during time of the (N−1)-th frame, the second-color light source202 may emit light, and in the during time of the N-th frame, thethird-color light source 203 may emit light. That is, during theoperation of the display device, the first-color light source 201, thesecond-color light source 202, and the third-color light source 203 mayemit light sequentially. In any three consecutive frames of the N framesdisplayed in one second, the first-color light source 201, thesecond-color light source 202, and the third-color light source 203 mayemit light, respectively.

In the disclosed embodiments, the field-sequential backlight module 200may provide a light source for the display panel 100. Thefield-sequential backlight module 200 may include the first-color lightsource 201, the second-color light source 202, and the third-color lightsource 203. In each frame, only the light sources emitting light in thesame single color may emit light in the field-sequential backlightmodule 200. That is, in each frame, the field-sequential backlightmodule 200 may only emit light of one color, such that the displaydevice may display a single color image in each frame.

For example, in one frame, the first-color light source 201 may emitlight, and the display device may display a first-color image,accordingly. Based on the persistence of vision of human eyes, threeconsecutive frames of images may be synthesized into one image to beobserved by the human eyes, and the one image to be observed by thehuman eyes is an image that the display device desires to display.

According to the disclosed driving method for the display device, thedisplay device may exhibit substantially high light transmittance. Inaddition, through utilizing the persistence of vision, three consecutiveframes of images may be synthesized into one image to be observed by thehuman eyes, enabling the display device to display images of richcolors.

In one embodiment, the three different color light sources may include ared light source, a green light source, and a blue light source. Thered, green, and blue are three primary colors of light, and thecombination of red, green, and blue colors may be able to realize all ofmost colors. Accordingly, the disclosed display device may be able todisplay images of multiple colors.

In the disclosed embodiments, on one hand, the display panel may includePDLCs, such that different gray scale images may be displayed withoutintroducing the polarizers to the display panel. On the other hand, thedisplay device may include the field-sequential backlight module, suchthat images in different colors may be displayed without introducing thecolor filters to the display panel. Because the disclosed display paneldoes not include any polarizers and any color filters, the lighttransmittance of the disclosed display device may be significantlyimproved as compared to the existing display device, thereby satisfyingthe demands of the transparent display technology.

According to the disclosed driving method for the display device, thedisplay device may exhibit substantially high light transmittance. Inaddition, through utilizing the persistence of vision, three consecutiveframes of images may be synthesized into one image to be observed by thehuman eyes, enabling the display device to display images of richcolors.

Various embodiments have been described to illustrate the operationprinciples and exemplary implementations. It should be understood bythose skilled in the art that the present disclosure is not limited tothe specific embodiments described herein and that various other obviouschanges, rearrangements, and substitutions will occur to those skilledin the art without departing from the scope of the disclosure. Thus,while the present disclosure has been described in detail with referenceto the above described embodiments, the present disclosure is notlimited to the above described embodiments, but may be embodied in otherequivalent forms without departing from the scope of the presentdisclosure, which is determined by the appended claims.

What is claimed is:
 1. A display device, comprising: a display panel,wherein the display panel includes a light incident surface and a lightexit surface arranged at a same side of the display panel; and afield-sequential backlight module arranged opposite to the displaypanel, wherein the field-sequential backlight module is disposed at aside of the display panel close to the light exit surface, and thefield-sequential backlight module includes a plurality of light sourcesof at least three different colors, wherein the display panel include afirst substrate, a second substrate disposed opposite to the firstsubstrate, and a liquid crystal layer sandwiched between the firstsubstrate and the second substrate, and the liquid crystal layer isconfigured to enable the display device to switch between an opaque ortranslucent state and a transparent state, without introducing anypolarizers to the display device, wherein the field-sequential backlightmodule includes a red light source, a green light source, and a bluelight source, wherein the display device displays N frames of images inone second (1 s), where N is an integer multiple of 3; in each of the Nframes, only one of the red light source, the green light source, andthe blue light source emits light; and in any three consecutive framesof the N frames, the red light source, the green light source and theblue light source emit the light, respectively.
 2. The display deviceaccording to claim 1, wherein: the liquid crystal layer includespolymer-dispersed liquid crystals (PDLCs).
 3. The display deviceaccording to claim 1, wherein: the first substrate includes a pluralityof pixels and a plurality of pixel electrodes; and the second substrateincludes a common electrode.
 4. The display device according to claim 3,wherein: a pixel electrode includes a reflective area, and thereflective area includes a reflective layer.
 5. The display deviceaccording to claim 3, further including: a reflective layer, wherein apixel electrode has a first side facing the second substrate and anopposite second side, and the reflective layer is disposed on the firstside of the pixel electrode, the reflective layer includes a pluralityof reflective elements, and an orthogonal projection of a reflectiveelement onto the pixel electrode is located inside the pixel electrode.6. The display device according to claim 3, wherein the first substratefurther includes: a plurality of scanning lines extending along a firstdirection and arranged along a second direction; a plurality of datalines extending along the second direction and arranged along the firstdirection; and a plurality of thin-film transistors (TFTs) one-to-onecorresponding to the plurality of pixel electrodes, wherein a pixelelectrode is electrically connected to a corresponding TFT.
 7. Thedisplay device according to claim 6, wherein: the plurality of pixelelectrodes are arranged along the first direction and the seconddirection to form a pixel electrode array.
 8. The display deviceaccording to claim 6, wherein: the plurality of pixel electrodes includea plurality of first pixel electrode columns and a plurality of secondpixel electrode columns alternately arranged in the first direction,wherein the pixel electrode in a first pixel electrode column isconfined in an area defined by two adjacent scanning lines and twoadjacent data lines, and the pixel electrode in a second pixel electrodecolumn is confined in an area defined by two adjacent data lines and,meanwhile, the pixel electrode in a second pixel electrode columnoverlaps with a scanning line.
 9. The display device according to claim6, further including: a plurality of long transparent regions withoutbeing disclosed with any pixel electrodes and any TFTs.
 10. The displaydevice according to claim 9, wherein: the plurality of scanning linesintersect the plurality of data lines to define a plurality of pixelregions; the pixel electrode is disposed in a pixel region; and thepixel region without being disclosed with the any pixel electrodes andthe any TFTs is a long transparent region.
 11. The display deviceaccording to claim 10, wherein: the plurality of pixel regions include aplurality of pixel groups; and a pixel group includes M number of pixelregions and one long transparent region, where M is a positive integerand M≥4.
 12. The display device according to claim 11, wherein: theplurality of pixel groups are arranged in an array, and the pixel regionis not disposed between two adjacent pixel groups.
 13. The displaydevice according to claim 11, wherein: the plurality of pixel groups andthe plurality of pixel regions are alternately arranged, and at leastone of the plurality of pixel regions is disposed between two adjacentpixel groups.
 14. The display device according to claim 1, wherein: thedisplay device is free of color filter and polarizers.
 15. A drivingmethod for a display panel comprising a display panel, wherein thedisplay panel includes a light incident surface and a light exit surfacearranged at a same side of the display panel; and a field-sequentialbacklight module arranged opposite to the display panel, wherein thefield-sequential backlight module is disposed at a side of the displaypanel close to the light exit surface, and the field-sequentialbacklight module includes a plurality of light sources of at least threedifferent colors, wherein the field-sequential backlight module includesa first-color light source, a second-color light source, and athird-color light source, the display panel include a first substrate, asecond substrate disposed opposite to the first substrate, and a liquidcrystal layer sandwiched between the first substrate and the secondsubstrate, and the liquid crystal layer is configured to enable thedisplay device to switch between an opaque or translucent state and atransparent state without introducing any polarizers to the displaydevice, wherein the driving method comprises: displaying, by the displaydevice, N frames of images in one second (1 s), where N is an integermultiple of 3; in each of the N frames, emitting light, by only one ofthe first-color light source, the second-color light source, and thethird-color light source; and in any three consecutive frames of the Nframes, emitting light, by the first-color light source, thesecond-color light source, and the third-color light source,respectively, wherein images of the three consecutive frames aresynthesized into one image observed by human eyes.
 16. The drivingmethod according to claim 15, wherein: the plurality of light sources ofthe at least three different colors include a red light source, a greenlight source, and a blue light source.
 17. The driving method accordingto claim 15, wherein: the liquid crystal layer includespolymer-dispersed liquid crystals (PDLCs).
 18. The driving methodaccording to claim 15, wherein: the display device is free of colorfilter and polarizers.